Dependent Drop Down Lists フォローする

I have three material types that I made a drop down list for.  Each of these material types has its own group of vendors we buy from.

Like in Excel (which I do know how to do), I need to make the second drop down list dependent on what I pick from the Material drop down list.  Can anyone help me do this?

I am very new to Bartender and I have some knowledge of Excel formulas, but no VB scripting experience.